Improvement in steam-gauges



JOIIN/ I. IIOLT, lOF CLEVELAND, OHIO.

' Letters Patent No. 70,213, dated October 29, 1867.

IMPROVEMENT IN STEAM-GAUGES.

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TO ALL WHOM IT MAY GONCERN:

Be it known that I, JOIIN I. HOLT, ofv Cleveland, in the county of Cuyahoga, and State of Ohio, have invented certain new and useful Improvements in Steam-Gauge; and I do hereby declare that the following is o. full and complete description of the same, reference being had to the accompanying drawings, making a partl of this specification, in which- Figure 1 is a front view ofthe gauge with the dial-plate detached.

Figure 2 is a side view. Figure 3, a vertical transverse section.

Figure 4, a detached section.,

Like letters of referencerefer to like parts inthovicws.

A,D fig. 1, is a. metallic shell, in which is secured a. small frame, B. In this frame is pivoted a bow, C, at!

g the point X. From the crown of this bow proceeds an armD, which is attaehed'to the bow by set-screws a,

inserted in slots so that the arm may be shortened or extended 'as circumstances may require. The bow C may be constructed with one arm, and chain E, iig. 2, isavshaft on which is keyed a spiral pulley, F, to which is attached in the middle the chains G, the ends being fastened to the extreme ends' of the bow, as shown inlig. 1. Also secured to this shaft is one end 'of a coiled spring, II, whereas the other end is secured to the frame, the purpose of which will presently be shown. I is a lever, having one end pivoted to a post, l, tig. 2, and the other connected to the arm D by means of a. link, K. This lever is also connected to a stem or rod, L, iig. 3,

tted loosely in the neck M, and terminated with a button, N, iig. 3, covered with an elastic disk, K. This button is also fitted loosely in the chamber N', formed by the enlargement or collar of the joint by which the apparatus is connected to the steam pipe or boiler. P, fig. 1, is a stout spring, the ends of which are bolted to the sides of the shell at the point X., and supported cndwise by the stays or abutment I, which 'receive and sustain the end pressure ot' the sprinc.' Through the-lower side of this spring passes the stem L to a shoulder, against which the under side of the spring rests'. On the protruded Vend of the stem is a nut, M, which, on being screwed down, confines the spring between the nut and shoulder; heneegle weight of the stemiand button is supported by the spring, and consequently does not hang upon 'the lever.

Having Athus described the several parts ofthe apparatus, and their arrangement, the operation ofthe same is as follows:

The gaugeis attached tofthe boiler by means of a steam pipe and'nut-joint, Q. The pressure of the steam is thereby brought to act directly on the button N, which forces it upward, more or less, according to the num -ber 0f pounds of steam carried. The spring at the` same time reacting or resisting this pl'essrurcwill'be forced up by the steam proportionately, and the stem being attached to the lever Il, and the lever to the arm D, will, as aconsequence, cause the bow to move in the direction ofthe arrow, "and thereby turn tholshaft E by means of the chain G wound partially around the pulley, but which will immediately unwind by the reaction of the spring H, as the pressure of the steam may diminish. New, a pointer fixed to the shaft, and which is indicated by tho red line, will turn with the shaft, andindicate on a dial, by which'the face of the gauge'is covered, the amount of pressure exerted on the button, which willbe that on the boiler. The peculiar construction of the mechan,

ism is such that a. very slight compression of the spring will produce a-movement of thc pointer to such a degree` as to be very obvious to the eye; thus the inward vcompression of the spring, ifnot more than one-sixtieth of an inch, will cause the pointer to moveseveralA inches around the index, and a complete revolution of the same around the dial will take place on forcing the spring upward not more than one-sixteenth of an inch; hence every degree of pressure is accurately noted on the dia-l from 0, or no pressure, as indicated by the red line c, to one hundred and seventy pounds, the highest that the boiler can carry with safety. The 4stem and button being fitted' loosely in each of their respective places, allows them to act freely and without the least possible restraint, so that the full effective pressure of the steam is free to act on the gauge, and thereby note every change that may take place in thepressure of the steam.' The manner of fastening the chain G to the pulley is shown in fig. 4. This pulley is providedwith a spiral {lange,`R, surrounding the middle, and by which the chain is kept from abrading upon' itselas it -s wound and unwound Vupon it. This flange is cut through from the periphery tothe base, and in which cutv is placed the chain. The ends of the cut are then closed upon it, which holds the chain securely from being displaced. 1 A

What I claim as my improvement, and desire to secure byLetters Iatent, is-

1. The arrangement of tlie lever I, link K, and adjusting-arm D with the bow C, chain G, and spindle E, substantially as set forth.

2. The combination of the abutments Il with the case A and spring R, substantially as herein set forth.

JOHN P. HOLT.

Witnesses:

W. H. Bunnrnen, E. E. WAITE. 

